conical shaped depressions were observed. The typical megafaunal 

 assemblage was observed at this mound as well. 



3.6.4 STNH-S 



The survey dive was conducted in a 13 cm/sec (0.25 knot) 

 current. The bottom consisted of fine silt (1 to 2 cm deep) over 

 a cohesive clay base. Small vertical burrows (0.5 cm diameter) 

 were common throughout the area (4-5 per m^) . Occasional 10 to 20 

 cm diameter burrows which had been dug horizontally into the clay 

 base were observed, and patches of hydroids (1 per 10 m^' were 

 common. Eroded clay clump material was also present. The vertical 

 relief over the survey dive was approximately 2 meters; major 

 bioturbators were mud snails, mysids, and whelks. 



3.6.5 Field Verification Program (FVP) Mound 



Two survey dives were conducted at the FVP mound 

 (center) . Current velocity was approximately 10 cm/sec (0.2 knot) . 

 The nepheloid layer in the survey area was less than 0.5 cm with 

 horizontal visibility approximately 1 meter. The bottom sediments 

 consisted of a thin oxidized layer of fine-grained silt over coarse 

 sand, grading into anoxic, loosely cohesive mud below. Shell hash 

 composed less than 1% surface cover. 



Predominant bioturbators were Pagurus longicarpus . P. 

 pollicaris . and Cancer irroratus . All were actively foraging in 

 surface sediments, creating sediment clouds which were carried away 

 by the current. More than 150 feeding excavation pits were 

 observed with a maximum density of 3 per m^. In addition to 

 general foraging activities, Pagurus longicarpus would burrow their 

 shells into the sediment surface and use chelae and mandibles to 

 winnow sediments. Juvenile Cancer irroratus (less than 2.5 cm 

 carapace width) excavated 2-3 cm deep vertical burrows for shelter. 

 All individuals of this size class were in softshell condition, and 

 exuviae were present at the entrance of many of the burrows. 



Starfish (Asterias forbesi ) and sand shrimp f Crangon 

 septemspinosa ) were observed in a foraging association. The shrimp 

 would winnow through sediments disturbed by the tube feet of 

 starfish as it moved over the bottom. The mud snail, Nassarius 

 trivittatuS f was attracted to the foraging excavations of 

 crustaceans and the plowed tracks of the whelk, Busycon carica . 

 Individual snails were observed to move directly to the area of 

 foraging activity. 



Juvenile finfish were also observed on the mound. Both 

 winter flounder, Psuedopleuronectes americanus . and four-spot 

 flounder, Paralichtvs oblongus, assumed normal foraging postures 

 during movements over the bottom. 



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